Of the world's legendary heroes, Robin Hood must surely be the most enchanting. He wasn't a nation-builder like William Tell, a revolutionary like Che or an idealist like Gandhi. He was a rustic outlaw with n'er a thought for politics. His creed wasn't liberty, equality or fraternity; it was merriment. For him, the redistribution of wealth wasn't an ideological goal; it was the by-product of adventure. The English could have chosen a Wat Tyler, Tom Paine or Henry V as their national champion. Instead, it was the witty escapades of a chivalrous rogue that won their hearts.

From the beginnings of cinema, film-makers sensed the allure of Sherwood's hero. By 1913, ­­five silents about Robin Hood had already appeared. Unfortunately, Hollywood could never convince itself that a mere greenwood archer could fill the big screen. In 1922, United Artists decided to make him the subject of the most expensive film that had ever been made. Yet its illustrious star, Douglas Fairbanks, was reluctant to play "a flat-footed Englishman walking through the woods". So his character turned into a political activist, fighting the wicked wiles of Prince John on behalf of noble King Richard.

The attractions of such aggrandisement weren't lost on the even more illustrious Errol Flynn. The character he played in The Adventures of Robin Hood in 1938 led a popular uprising against the Norman regime, trashed John's coronation, restored Richard to his rightful throne and ended up as an earl of the realm. Since this film secured not just critical acclaim and four Oscar nods but also a then-impressive $4m (£2.8m) in takings, its version of its protagonist became definitive. Subsequent efforts followed its lead by further traducing the personage of legend.

So Crowe's refusal to wear green tights in Robin Hood should have come as no surprise. In fact, under the tutelage of director Ridley Scott, he's done even more than his fellow antipodean predecessor to transmute a woodland robber into a historic titan. His self-appointed people's tribune heads off a civil war, persuades a king to promise a charter of rights, organises the defeat of an invading power and slays a traitor who's endangering the realm. He's righteous, compassionate and politically correct, but he could hardly be less merry.

Some say all of this is justified because it provides contemporary relevance. The film's Maid Marian, Cate Blanchett, thinks parallels with today's Britain are "there for the taking". Still, it's not too clear how these might help us. Evil King John is castigated for refusing to borrow from abroad, and taxing his people instead. Yet if Gordon Brown had followed his example, we might all be much better off. Rulers abuse their power, the poor go unrelieved and Muslim innocents fall foul of the English military. Maybe, but a portly brooding paragon doesn't seem like the kind of solution to such problems in which we should place much faith.

Ours isn't an age for secular messiahs. Scott says that hard times "always throw up someone", but today his claim rings hollow. In Flynn's time, the likes of Hitler, Churchill and FDR still looked to some like such a someone. Nowadays, we've learned to appreciate that no one's going to rescue us from the travails of harsh reality. When the Robin Hood myth was gaining hold, the horny-handed peasantry already seem to have clocked this. Perhaps that's why they chose the hero they did. They didn't expect to be redeemed, but they could at least hope to be entertained.

Heroes don't have to show us how to right the wrongs of the world. They can just try to cheer us up. Perhaps the next celluloid Robin Hood should be a Kick-Ass version. Suppose our hero were to kidnap a few wicked banker barons like Fred the Shred. He could drag them to the Sherwood Forest country park and torture them amusingly in the visitor centre. Once he'd extracted their ransom, he could distribute it to redundant Woolies workers.

Such a tale might not prove particularly uplifting, but it would be more in keeping with tradition.